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Characteristics of nanophase TiAl produced by inert gas condensation

Published online by Cambridge University Press:  31 January 2011

H. Chang
Affiliation:
Department of Materials Science and Engineering, University of Illinois at Urbana–Champaign, Urbana, Illinois 61801
C.J. Altstetter
Affiliation:
Department of Materials Science and Engineering, University of Illinois at Urbana–Champaign, Urbana, Illinois 61801
R.S. Averback
Affiliation:
Department of Materials Science and Engineering, University of Illinois at Urbana–Champaign, Urbana, Illinois 61801
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Abstract

Nanophase TiAl, with grain sizes in the range of 10–20 nm, was synthesized by magnetron sputtering in an inert gas atmosphere and consolidated, in situ, under vacuum. The properties of the powders and sintered compacts were studied by transmission electron microscopy, scanning electron microscopy, calorimetry, Rutherford backscattering, and x-ray diffraction. Samples compacted at 1.0 GPa at room temperature had a large fraction of amorphous phase, while samples compacted at the same pressure and 250 °C were predominantly the equilibrium γ phase. An enthalpy change of 22 kJ/g-atom was measured during a DSC scan over the temperature range 125–450 °C, which is approximately the range over which crystallization occurs. Nearly full density could be achieved by sintering at 450 °C without significant, concomitant grain growth. The Vickers microhardness of these samples at room temperature and at −30 °C revealed an inverse Hall–Petch relationship at small grain sizes, 10–30 nm, and the usual Hall–Petch behavior at larger grain sizes. A small component of indentation creep was also observed. The maximum hardness is 4 times larger than that of a cast TiAl specimen of the same composition. The Vickers hardness was also observed to decrease rapidly with temperature above 200 °C.

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Articles
Copyright
Copyright © Materials Research Society 1992

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References

1Lipsitt, H. A., in High-Temperature Ordered Intermetallic Alloys, edited by Koch, C. C., Liu, C. T., and Stoloff, N. S. (Mater. Res. Soc. Symp. Proc. 39, Pittsburgh, PA, 1985), p. 351.Google Scholar
2Aoki, K. and Izumi, O., J. Jpn. Inst. Met. 43, 358 (1979).CrossRefGoogle Scholar
3Liu, T. and Inouye, H., Metall. Trans. A 10A, 1515 (1979).CrossRefGoogle Scholar
4Brindley, P. K., in High-Temperature Ordered Intermetallic Alloys II, edited by Stoloff, N.S., Koch, C.C., Liu, C.T., and Izumi, O. (Mater. Res. Soc. Symp. Proc. 81, Pittsburgh, PA, 1987), p. 419.Google Scholar
5Schulson, E.M., Res. Mech. Lett. 1, 111 (1981).Google Scholar
6Inoue, A., Masumoto, T., and Tomioka, H., J. Mater. Sci. 19, 3097 (1984).CrossRefGoogle Scholar
7See, e.g., Granqvist, C. G. and Buhrman, R. A., J. Appl. Phys. 47, 2220 (1976).CrossRefGoogle Scholar
8Sherby, O. D. and Ruano, O. A., in Superplastic Forming of Structural Alloys, edited by Paton, N. E. and Hamilton, C. H. (TMSAIME, Warrendale, PA, 1982), p. 241.Google Scholar
9Brook, R. J., Proc. Brit. Ceram. Soc. 32, 7 (1982).Google Scholar
10Birringer, R. and Gleiter, H., Advances in Materials Science and Engineering, edited by Cahn, R. W. (Pergamon Press, New York, 1988), p. 339.Google Scholar
11Froes, F.H. and Suryanarayana, C., J. Metals 40, 12 (1989).Google Scholar
12Chang, H., Hofler, H. J., Altstetter, C. J., and Averback, R. S., Scripta Metall et Mater. 25, 1161 (1991).CrossRefGoogle Scholar
13Birringer, R., Gleiter, H., Klein, H. P., and Marquart, P., Phys. Lett. 102A, 365 (1984).CrossRefGoogle Scholar
14Chow, G. M., Chien, C. L., and Edelstein, A. S., J. Mater. Res. 6, 8 (1991).CrossRefGoogle Scholar
15Cullity, B.D., Elements of X-ray Diffraction, 2nd ed. (Addison-Wesley Publishing Co. Inc., Reading, MA, 1984), p. 102.Google Scholar
16Binary Alloy Phase Diagrams, 2nd ed., edited by Massalski, T. B. (ASM, Metals Park, OH, 1990), Vol. 1, p. 225.Google Scholar
17Averback, R.S., Hahn, H., Hofler, H.J., and Logas, J.C., Appl. Phys. Lett. 57, 1745 (1990).CrossRefGoogle Scholar
18Metals Reference Book, 5th ed., edited by Smithells, C. J. (Butterworths & Co. Ltd., Industrial Estate, Chichester, 1976), p. 193.Google Scholar
19CRC Handbook of Chemistry and Physics, 62nd ed., edited by Weast, R. C. (CRC Press Inc., Boca Raton, FL, 1983), p. B250.Google Scholar
20Miedema, A. R., Boer, F. R. De, and Boom, R., CALPHAD 1, 341 (1977).CrossRefGoogle Scholar
21Rupp, J. and Birringer, R., Phys. Rev. B 36, 7888 (1987).CrossRefGoogle Scholar
22Jang, J. S. C. and Koch, C. C., J. Mater. Res. 5, 498 (1990).CrossRefGoogle Scholar
23Hellstern, E., Fecht, H. J., Fu, Z., and Johnson, W. L., J. Appl. Phys. 65, 305 (1989).CrossRefGoogle Scholar
24Reed-Hill, R. E. and Abbaschian, R., Physical Metallurgy Principles, 3rd ed. (PWS-Kent Publishing Co., Boston, MA, 1992), p. 259.Google Scholar
25Hancock, G.F., Phys. Status Solidi A7, 535 (1971).CrossRefGoogle Scholar
26Shewmon, P. G., Transformations in Metals (McGraw-Hill, Inc., New York, 1969), p. 63.Google Scholar
27Chokski, A. H., Rosen, A., Karch, J., and Gleiter, H., Scripta Metall. 23, 1679 (1989).Google Scholar
28Lu, K., Wei, W.D., and Wang, J.T., Scripta Met. et Mater. 24, 2319 (1990).CrossRefGoogle Scholar
29Nieman, G. W., Weertman, J. R., and Siegel, R. W., J. Mater. Res. 6, 1012 (1991).CrossRefGoogle Scholar
30Gifkins, R. C., in Superplastic Forming of Structural Alloys, edited by Paton, N. E. and Hamilton, C. H. (TMS-AIME, Warrendale, PA, 1982), p. 3.Google Scholar
31Coble, R.L., J. Appl. Phys. 34, 1679 (1963).CrossRefGoogle Scholar
32Gleiter, H., Prog. Mater. Sci. 33, 298 (1989).CrossRefGoogle Scholar
33Li, W. B., Henshall, J. L., Hooper, R. M., and Easterling, K. E., Acta Metall. 39, 3099 (1991).CrossRefGoogle Scholar
34Ashby, M.F. and Verrall, R.A., Acta Metall. 21, 149 (1973).CrossRefGoogle Scholar
35Kim, Y.W., J. Metals 41, 24 (1989).Google Scholar